Investment
Investment Calculator
Project the future value of your investments with regular contributions.
Use CalculatorCompound Interest Calculator
See how your money could grow when interest earns interest. Add a starting balance and regular monthly contributions, then compare compounding frequencies.
How it works
Enter a starting amount, how much you'll add each month, an assumed annual interest rate and how many years to project.
Each month the balance grows by the equivalent monthly rate and your contribution is added at month end. The yearly table shows contributions, interest earned and the running balance.
Projections depend entirely on the interest rate you assume. Real-world returns vary and are not guaranteed.
Formula & methodology
A = P(1 + r/m)^(m·t) + contributions grown at the equivalent monthly rate
- P
- Initial investment
- r
- Annual interest rate
- m
- Compounding periods per year (365, 12, 4 or 1)
- t
- Years
To combine monthly contributions with any compounding frequency, the rate is converted to an equivalent monthly rate: (1 + r/m)^(m/12) − 1.
Taxes, fees and inflation are not included.
Illustrative example
$10,000 plus $200 a month
Assuming 7% compounded monthly for 20 years, total contributions are $58,000.
The projected balance is about $144,600, meaning roughly $86,600 comes from compound interest.
Hypothetical figures for illustration only.
Frequently asked questions
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